1 /* 2 * Copyright (C) 2011 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #ifndef ART_RUNTIME_JAVA_VM_EXT_H_ 18 #define ART_RUNTIME_JAVA_VM_EXT_H_ 19 20 #include "jni.h" 21 22 #include "base/macros.h" 23 #include "base/mutex.h" 24 #include "indirect_reference_table.h" 25 #include "obj_ptr.h" 26 #include "reference_table.h" 27 28 namespace art { 29 30 namespace mirror { 31 class Array; 32 } // namespace mirror 33 34 class ArtMethod; 35 class IsMarkedVisitor; 36 class Libraries; 37 class ParsedOptions; 38 class Runtime; 39 struct RuntimeArgumentMap; 40 41 class JavaVMExt; 42 // Hook definition for runtime plugins. 43 using GetEnvHook = jint (*)(JavaVMExt* vm, /*out*/void** new_env, jint version); 44 45 class JavaVMExt : public JavaVM { 46 public: 47 // Creates a new JavaVMExt object. 48 // Returns nullptr on error, in which case error_msg is set to a message 49 // describing the error. 50 static std::unique_ptr<JavaVMExt> Create(Runtime* runtime, 51 const RuntimeArgumentMap& runtime_options, 52 std::string* error_msg); 53 54 55 ~JavaVMExt(); 56 57 bool ForceCopy() const { 58 return force_copy_; 59 } 60 61 bool IsCheckJniEnabled() const { 62 return check_jni_; 63 } 64 65 bool IsTracingEnabled() const { 66 return tracing_enabled_; 67 } 68 69 Runtime* GetRuntime() const { 70 return runtime_; 71 } 72 73 void SetCheckJniAbortHook(void (*hook)(void*, const std::string&), void* data) { 74 check_jni_abort_hook_ = hook; 75 check_jni_abort_hook_data_ = data; 76 } 77 78 // Aborts execution unless there is an abort handler installed in which case it will return. Its 79 // therefore important that callers return after aborting as otherwise code following the abort 80 // will be executed in the abort handler case. 81 void JniAbort(const char* jni_function_name, const char* msg); 82 83 void JniAbortV(const char* jni_function_name, const char* fmt, va_list ap); 84 85 void JniAbortF(const char* jni_function_name, const char* fmt, ...) 86 __attribute__((__format__(__printf__, 3, 4))); 87 88 // If both "-Xcheck:jni" and "-Xjnitrace:" are enabled, we print trace messages 89 // when a native method that matches the -Xjnitrace argument calls a JNI function 90 // such as NewByteArray. 91 // If -verbose:third-party-jni is on, we want to log any JNI function calls 92 // made by a third-party native method. 93 bool ShouldTrace(ArtMethod* method) REQUIRES_SHARED(Locks::mutator_lock_); 94 95 /** 96 * Loads the given shared library. 'path' is an absolute pathname. 97 * 98 * Returns 'true' on success. On failure, sets 'error_msg' to a 99 * human-readable description of the error. 100 */ 101 bool LoadNativeLibrary(JNIEnv* env, 102 const std::string& path, 103 jobject class_loader, 104 jstring library_path, 105 std::string* error_msg); 106 107 // Unload native libraries with cleared class loaders. 108 void UnloadNativeLibraries() 109 REQUIRES(!Locks::jni_libraries_lock_) 110 REQUIRES_SHARED(Locks::mutator_lock_); 111 112 /** 113 * Returns a pointer to the code for the native method 'm', found 114 * using dlsym(3) on every native library that's been loaded so far. 115 */ 116 void* FindCodeForNativeMethod(ArtMethod* m) 117 REQUIRES_SHARED(Locks::mutator_lock_); 118 119 void DumpForSigQuit(std::ostream& os) 120 REQUIRES(!Locks::jni_libraries_lock_, 121 !Locks::jni_globals_lock_, 122 !Locks::jni_weak_globals_lock_); 123 124 void DumpReferenceTables(std::ostream& os) 125 REQUIRES_SHARED(Locks::mutator_lock_) 126 REQUIRES(!Locks::jni_globals_lock_, !Locks::jni_weak_globals_lock_); 127 128 bool SetCheckJniEnabled(bool enabled); 129 130 void VisitRoots(RootVisitor* visitor) REQUIRES_SHARED(Locks::mutator_lock_) 131 REQUIRES(!Locks::jni_globals_lock_); 132 133 void DisallowNewWeakGlobals() 134 REQUIRES_SHARED(Locks::mutator_lock_) 135 REQUIRES(!Locks::jni_weak_globals_lock_); 136 void AllowNewWeakGlobals() 137 REQUIRES_SHARED(Locks::mutator_lock_) 138 REQUIRES(!Locks::jni_weak_globals_lock_); 139 void BroadcastForNewWeakGlobals() 140 REQUIRES(!Locks::jni_weak_globals_lock_); 141 142 jobject AddGlobalRef(Thread* self, ObjPtr<mirror::Object> obj) 143 REQUIRES_SHARED(Locks::mutator_lock_) 144 REQUIRES(!Locks::jni_globals_lock_); 145 146 jweak AddWeakGlobalRef(Thread* self, ObjPtr<mirror::Object> obj) 147 REQUIRES_SHARED(Locks::mutator_lock_) 148 REQUIRES(!Locks::jni_weak_globals_lock_); 149 150 void DeleteGlobalRef(Thread* self, jobject obj) REQUIRES(!Locks::jni_globals_lock_); 151 152 void DeleteWeakGlobalRef(Thread* self, jweak obj) REQUIRES(!Locks::jni_weak_globals_lock_); 153 154 void SweepJniWeakGlobals(IsMarkedVisitor* visitor) 155 REQUIRES_SHARED(Locks::mutator_lock_) 156 REQUIRES(!Locks::jni_weak_globals_lock_); 157 158 ObjPtr<mirror::Object> DecodeGlobal(IndirectRef ref) 159 REQUIRES_SHARED(Locks::mutator_lock_); 160 161 void UpdateGlobal(Thread* self, IndirectRef ref, ObjPtr<mirror::Object> result) 162 REQUIRES_SHARED(Locks::mutator_lock_) 163 REQUIRES(!Locks::jni_globals_lock_); 164 165 ObjPtr<mirror::Object> DecodeWeakGlobal(Thread* self, IndirectRef ref) 166 REQUIRES_SHARED(Locks::mutator_lock_) 167 REQUIRES(!Locks::jni_weak_globals_lock_); 168 169 ObjPtr<mirror::Object> DecodeWeakGlobalLocked(Thread* self, IndirectRef ref) 170 REQUIRES_SHARED(Locks::mutator_lock_) 171 REQUIRES(Locks::jni_weak_globals_lock_); 172 173 // Like DecodeWeakGlobal() but to be used only during a runtime shutdown where self may be 174 // null. 175 ObjPtr<mirror::Object> DecodeWeakGlobalDuringShutdown(Thread* self, IndirectRef ref) 176 REQUIRES_SHARED(Locks::mutator_lock_) 177 REQUIRES(!Locks::jni_weak_globals_lock_); 178 179 // Checks if the weak global ref has been cleared by the GC without decode (read barrier.) 180 bool IsWeakGlobalCleared(Thread* self, IndirectRef ref) 181 REQUIRES_SHARED(Locks::mutator_lock_) 182 REQUIRES(!Locks::jni_weak_globals_lock_); 183 184 void UpdateWeakGlobal(Thread* self, IndirectRef ref, ObjPtr<mirror::Object> result) 185 REQUIRES_SHARED(Locks::mutator_lock_) 186 REQUIRES(!Locks::jni_weak_globals_lock_); 187 188 const JNIInvokeInterface* GetUncheckedFunctions() const { 189 return unchecked_functions_; 190 } 191 192 void TrimGlobals() REQUIRES_SHARED(Locks::mutator_lock_) 193 REQUIRES(!Locks::jni_globals_lock_); 194 195 jint HandleGetEnv(/*out*/void** env, jint version); 196 197 void AddEnvironmentHook(GetEnvHook hook); 198 199 static bool IsBadJniVersion(int version); 200 201 private: 202 // The constructor should not be called directly. It may leave the object in 203 // an erroneous state, and the result needs to be checked. 204 JavaVMExt(Runtime* runtime, const RuntimeArgumentMap& runtime_options, std::string* error_msg); 205 206 // Return true if self can currently access weak globals. 207 bool MayAccessWeakGlobalsUnlocked(Thread* self) const REQUIRES_SHARED(Locks::mutator_lock_); 208 bool MayAccessWeakGlobals(Thread* self) const 209 REQUIRES_SHARED(Locks::mutator_lock_) 210 REQUIRES(Locks::jni_weak_globals_lock_); 211 212 Runtime* const runtime_; 213 214 // Used for testing. By default, we'll LOG(FATAL) the reason. 215 void (*check_jni_abort_hook_)(void* data, const std::string& reason); 216 void* check_jni_abort_hook_data_; 217 218 // Extra checking. 219 bool check_jni_; 220 bool force_copy_; 221 const bool tracing_enabled_; 222 223 // Extra diagnostics. 224 const std::string trace_; 225 226 // Not guarded by globals_lock since we sometimes use SynchronizedGet in Thread::DecodeJObject. 227 IndirectReferenceTable globals_; 228 229 // No lock annotation since UnloadNativeLibraries is called on libraries_ but locks the 230 // jni_libraries_lock_ internally. 231 std::unique_ptr<Libraries> libraries_; 232 233 // Used by -Xcheck:jni. 234 const JNIInvokeInterface* const unchecked_functions_; 235 236 // Since weak_globals_ contain weak roots, be careful not to 237 // directly access the object references in it. Use Get() with the 238 // read barrier enabled. 239 // Not guarded by weak_globals_lock since we may use SynchronizedGet in DecodeWeakGlobal. 240 IndirectReferenceTable weak_globals_; 241 // Not guarded by weak_globals_lock since we may use SynchronizedGet in DecodeWeakGlobal. 242 Atomic<bool> allow_accessing_weak_globals_; 243 ConditionVariable weak_globals_add_condition_ GUARDED_BY(Locks::jni_weak_globals_lock_); 244 245 // TODO Maybe move this to Runtime. 246 std::vector<GetEnvHook> env_hooks_; 247 248 DISALLOW_COPY_AND_ASSIGN(JavaVMExt); 249 }; 250 251 } // namespace art 252 253 #endif // ART_RUNTIME_JAVA_VM_EXT_H_ 254
